Thrust reverser systems are known for example from documents FR 2 935 444 and FR 2 935 354. Amongst the different thrust reverser principles implemented in aircraft turbine engines, reversal cascade systems are known provided with passages oriented such as to direct the air obtained from the secondary flow duct forwards in order to generate the counter-thrust force. The air is forced to be extracted from this secondary flow duct by reverser doors which close this flow duct at least partially in the active configuration of the system.
On the other hand, in the inactive configuration, each reverser door is in the retracted position in which it participates in the formation of the outer wall of the secondary flow duct, also known as the OFS (Outer Fixed Structure). More specifically, in this inactive configuration of the reverser system, each door constitutes part of this outer wall of the secondary flow duct, within a nacelle outer mobile cowling containing the reversal cascade. During the transition from the inactive configuration to the active configuration, the outer mobile cowling is displaced rearwards by actuators, such as to clear the cascade, and bring the reverser doors into their position of closing of the secondary flow duct, by means of appropriate mechanical kinematics.
Although this principle is extensively applied, it nevertheless suffers from a problem of aerodynamic perturbations of the flow of air which passes through the secondary flow duct in the inactive configuration of the system. In fact, in this configuration, the flow of air within the secondary flow duct is perturbed during its passage to the areas of joining between the body of the outer mobile cowling and the reverser doors which are added onto this body. This perturbation is derived from the drag as well as from the pressure losses within the secondary flow duct, which lead to a decrease in the overall performance of the turbine engine.